Critical Thinking Exercise 1
“Visual Cortex”
The diagnosis behind a person’s vision problem is one that is difficult to pin down since there are many areas where problems can arise. In certain cases different parts of the eye could be the problem. In others it could actually be the passageway between the eye and the end location in the brain that could be the culprit. In order to figure out where the problem occurs a series of specific questions must be asked, thus narrowing the possibilities of the problem and increase the likelihood of a solution being found.
Question 1: Are you experiencing a loss of color vision?
If the person is actually suffering from a loss of color vision then the problem is most likely a result of some damage to the cones. There are 3 different types of cones in the eye; small, medium, and large cones. Each type of cone registers different wavelengths of light. If the cones aren’t working properly then certain ranges of colors or even all the colors will not be visible because the cone isn’t able to detect that wavelength of light.
Question 2: Are you having trouble seeing at night?
The ability to adapt to the dark requires a transition to an increase in usage of rods. Rod cells function better than cones at low intensities of light so the problem of having trouble seeing in the dark is one that is within the eye. Since rods and cones are an extension of the neural system in the brain the problem is not just optical but neural as well.

Question 3: Are you unable to perceive motion?
If the answer to this question is yes, the problem is most likely a result of the person sustaining an injury to the dorsal stream. A main function of the dorsal stream is visually guided behavior and being able to find objects in space. If the person was suffering from an inability to perceive motion and locate objects in a room or around them then the most likely explanation is that the person’s dorsal stream has been compromised and the subject is suffering from Akinetopsia.
Question 4: Are you having trouble being